Overload attachment for semielliptical springs



Patented Aug. 19, 1952 UNITED OVERLOAD ATTACHlWENT FOR SEMI- ELLIPTICAL SPRINGS Herbert D. Boardman and Fritz Hansen,

' Manchester, Iowa Application April 8, 1949, Serial No. 86,328

2 Claims.

Our invention relates to overload attachments for semi-elliptical springs, and more particularly to such springs as are utilized in motor vehicles. As is well known, such semi-elliptical springs when subjected to long use and/or to overloads tend to flatten out, whereby to lose a considerable amount of their effectiveness.

With the foregoing in view, it is an object of our invention to provide an improved overload attachment for semi-elliptical springs.

A further object is to provide an improved overload attachment for semi-elliptical springs which includes an overload spring, means resiliently connecting opposite ends of the overload spring to opposite ends of the semi-elliptical spring, and rigid upwardly-extending extensions of said means resiliently loaded into supporting engagement with the semi-elliptical spring laterally inwardly of said opposite ends thereof.

Other objects and advantages reside in the particular structure of the invention, combination and arrangement of the several parts thereof, and will be readily understood by those skilled in the art upon reference to the attached drawing in connection with the following specification, wherein the invention is shown, described and claimed.

In the drawing:

Figure 1 is a fragmentary front elevation of a motor vehicle and a semi-elliptical spring therefor, showing the attachment according to the invention applied thereto;

Figure 2' is a horizontal sectional view taken substantially on the plane of the line 22 of Figure 1;

Figure 3 is a bottom plan view of the attachment in place on a semi-elliptical spring;

Figure 4 is a transverse vertical sectional view taken substantially on the plane of the line 4-4 of Figure 1, parts being omitted;

Figure 5 is a perspective view of an anchor member according to the invention apart from the rest of the structure.

Referring specifically to the drawing, wherein like reference characters have been used throughout the several views to designate like parts, In designates generally any suitable portion of the frame of a motor vehicle and II designates generally a semi-elliptical spring for the vehicle The spring H is operatively connected to the frame In in any usual and/or well known manner, as by the center bolt [3 and U-bolts H. The opposite ends l5 of the spring II are pivotally supported in the usual manner from spring shackles I6 connected to the axle ll of the vehicle.

The device according to our invention includes a pair of hooks or anchor-providing means, generally indicated at I8, and best seen in Figure 5. In view of the fact that both of the anchors l8 are identical, it will sufiice to describe but a single one of them. Thus, each anchor l8 includes a horizontally-disposed leg I!) and an upwardly-directed rigid arm 20 integral with the leg [9 to provide a substantially L-shaped anchor. Each anchor I8 has an upwardly-directed hook 2| formed integrally with the free end of the horizontal leg l9 thereof. As best seen in Figure 1, the hooks 2! are hooked over the opposite ends of the leaf spring ll so as to dispose the horizontal legs I9 of the anchors I8 in oppositely-inwardly-directed relation below the leaf spring II. The upstanding arms 20 of the anchors i8 have aligned holes 25, Figure 5, formed therethrough for the free passage of the shanks of a pair of inwardly-directed eye bolts 22. A contractile overload spring 23 is: operatively connected to the eyes of the eye bolts 22 and is maintained in an adjusted tensioned condition by means of nuts 24 threaded on the shanks of the eye bolts 22 outwardly of the upwardly-directed arms 20 of the anchors I8. I As best seen in Figure 1, the lines AA represent the horizontal plane of the pivotal axes of the pivotal connection of the hooks 2| with the opposite ends [5 of the leaf spring ll. Also, the line B-B of Figure 1 represents the horizontal plane through the bolts 22 and axis of the spring 23. It is noted that the plane of the line B-B is slightly below the plane of the line AA, whereby the effect of the spring 23 is to load the upstanding arms 20 into supporting engagement with the under side of the leaf spring II between the opposite ends l5 thereof and the intermediate portion l2. effect, the points 26 where the upper ends of the arms 20 engage the under side of the spring ll comprise fulcrum-providing points about which the opposite ends [5 of the leaf spring are flexed under the load-of the overload spring 23. Thus, not only does the overload spring 23 resist the flattening of the leaf spring H under a load by an inward pull on the opposite ends [5 thereof, but also resists such flattening by the upward thrust of the arms 20 on the under surface of the spring.

While we have shown and described what is now believed to be a preferred embodiment of the invention, it is to be understood that our invention is susceptible to other forms and expressions. Consequently, we do not limit ourselves to the precise structure shown and de- 3 scribed hereinabove except as hereinafter claimed.

We claim:

1. The combination with a vehicle having a pair of spaced spring shackles, a semi-elliptical leaf spring pivotally supported at its opposite ends by said shackles, said spring having an upwardly bowed intermediate portion supporting aload, of a pair of L-shaped anchors each positioned below said leaf spring and adjacent an end of the latter, the horizontal leg'of each of said anchors being formed adjacent its free' end with an upwardly directed hook, said hooks releasably and pivotally engaging the adjacent ends of said leaf springs, the vertical legs of the. anchors being in confronting relation and being vertically arranged under the leaf spring, and

, leaf spring pivotally supported at its opposite ends by said shackles, said spring having an upwardly bowed intermediate portion supporting a load, of a pair of L-shaped anchors each positioned below said leaf spring and adjacent an end of the latter, the horizontal leg of each of said anchors being formed adjacent its free end with an upwardly directed hook, said hooks releasably'and pivotally engaging the adjacent ends oi said leaf springs, and a "coil spring operatively secured at its opposite ends to the vertical legs of said anchors below a line drawn between-the pivotal engagement points of said hooks with the adjacent ends of said leaf spring, said coil spring connecting said vertical legs to- -gether for normally urging the latter toward REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS NaIne Date Kucera Dec. 28, 1948 Number 

